1. FIELD OF THE INVENTION
The present invention relates to an improvement in a float device for a small size boat provided in its body with a float made of foamed plastic in order to keep a necessary buoyancy in case of submergence.
2. DESCRIPTION OF THE PRIOR ART
For example, in a small size boat to be manipulated from a standing or sitting posture, a float made of foamed plastic is provided at a rear side of a body constituted by deck and hull, so that necessary buoyancy may be kept even if the deck or the hull is damaged (refer to Japanese Patent Publication No. 3879/78).
The float is made solely of either hard foamed plastic of high density or soft formed plastic of low density.
In the case where a driver's weight load is applied onto a floor of the deck, if the float is made of hard material, a local high stress is likely to be applied to the floor. It is therefore necessary to further increase the mechanical strength of the materials of the floor and the float.
On the other hand, if the float is made of soft material, a force applied to the float is widely dispersed but the deformation per se will become large. This is not convenient for reducing a stress applied to the deck.
Such a float has sometimes been formed by foaming the material in the working site. However, without foaming the material in the working site, a foamed body formed, in advance, in a mold has frequently been inserted into a boat body. In this case, if the foamed material is soft, it may be made to fit the boat body. However, if the foamed material is hard it is difficult to make the foamed body fit with the boat body in assembly. In the latter case, a dimensional error would cause an undesired clearance or gap to be generated between the boat body and the foamed body.